Within the last few weeks at our company we have been doing testing to
find out total number of patched machines we have against the latest
Messenger Service Vulnerability. After checking few thousand computers
we have found several hundred were still affected even though patch has
been applied. We have scanned with Retina, Foundstone and Qualys tools
which they all showed as ?VULNERABLE?, however when we scanned with Microsoft
Base Security Analyzer it showed as ?NOT VULNERABLE?. This was at first
confusing; one would think an assessment tool released by the original
vendor would actually be accurate. On the flipside it really didn?t make
sense to us why would three different commercial scanners show as vulnerable
if they are truly patched. So we decided to do the ultimate test. We
ran messenger service exploit against the machines that MS Base Analyzer
showed as ?Not Vulnerable? and 3rd party vulnerability scanners that
showed as ?Vulnerable?. Results were as expected, machines were exploited
and Microsoft Base Analyzer failed to detect the vulnerable machines
properly.

We have concluded that, although the patch was installed on these machines,
the patch management script failed to reboot those few hundred systems,
therefore these machines were vulnerable until the next successful reboot.
After a successful reboot all 3rd party tools showed the machines as
not vulnerable and the exploit tool did not successfully exploit the
machines. 3rd Party tool assessments were accurate the machines were
truly vulnerable prior reboot.

Had we trusted Microsoft Base Analyzer we would still be vulnerable.

To prove this, I have captured screen shots and converted them in pdf
format for your viewing pleasure. The screenshots shows exact same scan
conducted with Foundstone tool and MBSA.

Screenshots: http://www.elusiveworld.com/scanshots.pdf

I would love to see if there are any more like us out there who encountered
this problem. If you had similar problems our recommendation to you do
not fully depend on MBSA, since the tool is just as buggy as the company
itself.